Edge guard for buffing machine

ABSTRACT

The present invention discloses an edge guard for a buffer pad. The buffed pad is formed of a canvas backing provided with a nap of wool on the front working surface thereof. The edge guard is similarly formed of a canvas backing with a wool nap, but the nap therefor is on the back surface of the canvas backing and only extends about an annular area adjacent to the outer circumference thereof. During the assembly of the buffer pad on a circular rubber back-up disc that is used for holding the buffer pad on the projecting end of a driving spindle, the edge guard pad is first positioned on the back-up disc with the back surface of its canvas backing against the back-up disc such that the annular area provided with the nap of wool surrounds and extends beyond the outer circumferential edge of the back-up disc. Then the buffer pad is positioned on the back-up disc with the back surface of its canvas backing against the front surface of the edge guard pad. The assembly is then fastened together by a clamping nut.

United States Patent 1 Wakefield 1 1 EDGE GUARD FOR BUFFING MACHINE [75]Inventor: Orval W. Wakefield, Cypress, Calif.

[73] Assignee: Pit-Bar Manufacturing Company,

Los Angeles, Calif.

22 Filed: May 6,1971

[21] Appl. No.: 140,683

[52] US. Cl ..15/97 R, l5/230.l5, l5/230.l9 [51] Int. Cl. ..A47l11/14[58] Field of Search ..15/230.19, 230.18, 230.17, 15/230.l6, 230.15,230.14, 230.12, 230, 97,

Primary EXaminerLeon G. Machlin Attorney-Beehler, Arant & Jagger [45]Feb. 27', 1973 [57] ABSTRACT The present invention discloses an edgeguard for a buffer pad. The buffed pad is formed of a canvas backingprovided with a nap of wool on the front working surface thereof. Theedge guard is similarly formed of a canvas backing with a wool nap, butthe nap therefor is on the back surface of the canvas backing and onlyextends about an annular area adjacent to the outer circumferencethereof. During the assembly of the buffer pad on a circular rubberbackup disc that is used for holding the buffer pad on the projectingend of a driving spindle, the edge guard pad is first positioned on theback-up disc with the back surface of its canvas backing against theback-up disc such that the annular area provided with the nap of woolsurrounds and extends beyond the outer circumferential edge of theback-up disc. Then the buffer pad is positioned on the back-up disc withthe back surface of its canvas backing against the front surface of theedge guard pad. The assembly is then fastened together by a clampingnut.

4 Claims, 4 Drawing Figures PAIENTEUFEBZYW 3.717, 894

0/91/41. M/ Wd/(fF/EL AI INVENTOR.

EDGE GUARD FOR BUFFING MACHINE This invention relates to power drivenbuffer pads for use in the automotive service field, for example, andmore particularly to an improvement in the form of an edge guard forsuch a buffer pad.

When using hand operated power driven buffer pads for polishing thesurfaces of automobiles and similar equipment, it is conventional toprovide a circular canvas backing with a nap of wool on the outer orworking surface thereof. While the nap so formed by the wool tends tolean outwardly such as to extend beyond the outer circumferential edgeof the circular canvas backing, this form of construction neverthelessleaves the sharp outer edge and the rear portion of the canvas backingexposed. Thus during the use of the rotating buffer pad and especiallywhen encountering sharp contours on the surface of the automobile duringthe buffing operation, extra precaution is required of the operator toprevent the outer edge and exposed rear portion of the canvas backingfrom marring or otherwise defacing the surface which is intended to bepolished.

Accordingly the present invention forms an improvement in buffer deviceswhich provides for covering the edge and outer rear portions of thecanvas backing of a buffer pad and thus guards these portions fromdamaging the surface to be bufi'ed.

Another object of the invention is to provide an edge guard for aconventional buffer pad which is simply formed and which is adapted tobe readily attached to a rotatable back-up disc provided for the bufferpad.

These and other objects and advantages of the present invention will bemore clearly understood by reference to the following description andthe accompanying drawings in which:

FIG. 1 is a top plan view of the buffer pad device of the presentinvention.

- FIG. 2 is a cross-sectional view of the buffer pad device as viewedalong lines 2-2 of FIG. 1.

FIG. 3 is a cross-sectional view of the attachment device for the bufferpad device as taken along lines 3-3 of FIG. 2.

FIG. 4 is an exploded view of the parts comprising the buffer paddevice.

Referring to the drawings, a buffing machine generally noted by thereference numeral includes a pad assembly 11 comprising a buffer pad 12and an edge guard 14 pad. The buffer pad 12 is provided with a backingformed of a circular sheet of canvas 15 having a central opening 20.Tufts of lamb's wool are sewn on the front surface of the canvas 15 toform a nap 17. The tufts of wool forming nap 17 extend in a directionsubstantially normal to the surface of the canvas 15 throughout most ofthe working surface of the pad 12. However, in the region of the centralopening 20 pro vided on the canvas 15 the nap 17 tends to lean radiallyinward and in the region of the outer circumference of the canvas 15 thenap 17 tends to lean radially outwardly such that part of it liessubstantially in the same plane as the canvas 15. A second circularsheet of canvas 19 is glued over the canvas 15 for the purpose ofcovering up the ends of the tufts of wool sewn thereon and for furtherreinforcing the backing. The canvas 19 has the same outer diameter asthe canvas 15 and a similar central opening 20.

The edge guard pad 14 is similarly provided with a backing formed of acircular sheet of canvas 21 having the same outer diameter as canvas 15and a similar central opening 20. In the fabrication of the edge guardpad 14, tufts of lamb's wool are sewn on outer annular portion 21a onlyof the rear surface of canvas 21 to provide a nap 23. As indicated, nap23 tends to lean inwardly at the inner radius of annular portion 21a andtends to lean outwardly at the outer radius thereof such that part ofthe nap lies substantially in the same plane as the canvas 21. The edgeguard pad 14 has a second circular sheet of canvas 24 which is gluedonto canvas 21 for the purpose of covering the sewn ends of the wool andfurther enforcing the backing therefor. The buffer pad 12 and the edgeguard pad 14 when positioned with their canvas backings back-to-backform the buffer pad assembly 11 of the present invention. It should benoted that when so combined the nap 17 on the outer edge of the bufferpad 12 and the nap 23 on the outer edge of the edge guard pad 14 tend tolean radially outwardly such that they meet in the common plane of theircanvas backings.

In order to rotate the buffer pad assembly 11, it is held on a rotatableback-up plate 30 which is adapted to be mounted on a spindle 47 of apower driven unit. The back-up plate 30 comprises a relatively hard,flat, rubber disc 31 provided with a central opening 32. The disc 31 hasa diameter smaller than the canvas backing of buffer unit 11 such as togive a sufficient degree of rigidity thereto while permitting the outercircumferential edge portion of the canvas backing to be free to bendwhen under pressure. A metal center holder 34 for the disc 31 is formedof a cup 35 with an outer flange 36 on the upper end thereof. A metalcover 37 is provided for cooperating with the flange 36. The inner edgeportion of the central opening 32 of the rubber disc 31 is held betweenthe outer :flange 36 of the cup 35 and the cover 37 therefor andsecurely clamped in position by a number of equally spaced rivets 38.

The metal holder 34 has a central opening 40 in the bottom of the cup 35for receiving the projected threaded end 42 of the spindle 47. The cover37 of the cup 35 is provided with a central opening 48 formed with threeequally spaced flat sides 50 which conform with flats 51 on the body ofa clamp nut 52 provided with a cap 53 on the upper end thereof. Thus thebody of the clamp nut 52 is inserted through the central opening 20 ofthe canvas backing for the buffer pad 12 and edge guard pad 14 andthrough the central opening 48 of the cover 37 such that the flats 51provided on the body of the nut 52 engage the flat sides 50 provided inthe opening 48. The nut 52 is thus engaged to the cover 37 such that thyrotate as a single member. Then when the threaded projected end 42 ofthe spindle 47 is threadably engaged on the clamping nut 52, the top 53engages the inner edge of the central opening of the canvas backing forthe pads and securely clamps them against the upper surface of the cover37.

When the buffer unit 11 of the present invention is to be used, theparts are assembled together in the following order as best shown by thereference to FIG. 4. First the buffing device is held with its spindle47 in an upright position, and the back-up plate 30 is dropped over theend of the spindle 47 such that the bottom of the cup 35 of the metalcenter holder 34 for the backup plate 30 rests on the shoulder 45 of thespindle 47, and the projected threaded end 42 of spindle 47 extendsupwardly through the central opening 40 in the bottom of the cup 34.Then the edge guard pad 14 is placed on the back-up plate 30 with theinner radius of the annular portion 21a thereof adjacent the peripheraledge of the disc 31. It should be noted that the edge guard pad 14 isput on backwards in the sense that the nap 23 on the annular portion 21aextends generally downward in direction. When so positioned the nap nearthe inner radius of annular portion 21a leans radially inwardly aboutthe outer edge of disc 31 and the nap near the outer radius thereofleans radially outwardly such as to lie substantially in the same planeas the canvas 21. Next the buffer pad 12 with the nap 17 on its workingsurface facing in the upper direction is dropped over the exposed canvassurface of the edge guard pad 14. When the pads 12 and 14 are sopositioned on the back-up plate 30, the projecting end 42 of the spindle47 extends upwardly through the center opening 20 of the pad assembly.The clamp nut 52 is then inserted through the center opening 20 from thefront of the pad assembly such that the body of the clamp nut fits inthe opening of the cover 37, and the cap 53 of the clamp nut 57 engagesthe edge portion of the center opening 20 of the canvas backing. Thethreaded projected end 42 of the spindle 47 is then advanced on to thenut 52 such as to clamp the edges of the center opening between the cap53 and the cover 37 of the center holder 34 and the assembly is thencompleted. It should be particularly noted that with the edge guard pad14 in position on the buffer pad 12, the sharp outer edge and outer rearportions of the canvas backing for the buffer pad 12 is completelycovered by the nap of lambs wool extending from the edges of the padssuch as to insure that no portions of the canvas backing are exposedwhich could inadvertently mar the surface being polished by the bufferpad.

While the description has been concerned with a particular structuralembodiment, it is to be understood that modifications and variations inthe construction and arrangement may be provided for without departingfrom the spirit and scope of the invention or sacrificing any of itsadvantages. The invention is therefor considered as including all suchpossible modifications and variations coming within the legitimate andvalid scope of the appended claims:

What is claimed is:

l. A buffing device comprising:

a buffer pad including a circular canvas backing and a nap of woolattached to the front surface of said backing;

an edge guard pad having a circular canvas backing of comparable size tosaid canvas backing of said buffer pad, and having a nap of woolattached to the outer annular area of the rear surface of its saidcircular canvas backing;

said pads being assembled with the front surface of the canvas backingfor said edge guard pad engaging the rear surface of the canvas backingfor said buffer pad, the nap on the outer circumferential edge of thefront surface of said buffer pad and the nap on the outercircumferential edge of the rear surface of said edge guard pad bothtending to lean radial] outward such that they meet in the common planeof the canvas backings and thereby protect any object being buffed frombeing directly. engaged by the circumferential edges of said canvasbackings;

a resilient circular backup plate having a radius equal to the innerradius of the outer annular area of the rear surface of said edge guardpad, said backup plate being in engagement with said rear surface; and

fastening means coupling the centers of said buffer pad, said edge guardpad, and said backup plate to each other, and adapted for attachment tothe end of a rotatable drive shaft.

2. A buffing machine of the type used in the automotive service fieldand for other purposes including:

a buffer pad comprising a circular canvas backing provided with a nap ofwool on the front surface thereof,

an edge guard pad comprising a circular canvas backing provided with anap of wool on the outer annular area of the rear surface thereof,

said pads being assembled with the rear surface of the canvas backingfor the buffer pad held adjacent the front surface of the canvas backingfor the edge guard pad,

the nap on the outer circumferential edge of the front surface of thebuffer pad and the nap on the outer circumferential edge of the rearsurface of the edge guard pad tending to lean radially outwardly suchthat they meet in the common plane of the canvas backings for the padsand thereby provide for covering the circumferential edge of said bufferpad,

a circular backup plate for said buffer pad, and

said circular backup plate having a radius equal to the inner radius ofthe outer annular area on the rear surface of the canvas backing of theedge guard pad that is provided with a nap of wool.

3. The invention in accordance with claim 2 wherein said circularback-up plate is formed of rubber.

4. The invention in accordance with claim 3 wherein said buffer and edgeguard pad assembly is provided with a central opening,

wherein said back-up plate is provided with a central opening in linewith the central opening of said pad assembly, and

wherein said buffing machine includes a driving spindle having athreaded projected end that extends from the rear of said back-up platethrough the central opening of said back-up plate and said pad assembly,and

a clamping nut provided with a cap,

said nut being inserted from the front of said pad assembly into thecentral opening thereof such as to engage the threaded projected end ofsaid spindle to enable the cap thereon to clamp the inner edge of thecentral opening of said pad assembly against said back-up plate.

1. A buffing device comprising: a buffer pad including a circular canvasbacking and a nap of wool attached to the front surface of said backing;an edge guard pad having a circular canvas backing of comparable size tosaid canvas backing of said buffer pad, and having a nap of woolattached to the outer annular area of the rear surface of its saidcircular canvas backing; said pads being assembled with the frontsurface of the canvas backing for said edge guard pad engaging the rearsurface of the canvas backing for said buffer pad, the nap on the outercircumferential edge of the front surface of said buffer pad and the napon the outer circumferential edge of the rear surface of said edge guardpad both tending to lean radially outward such that they meet in thecommon plane of the canvas backings and thereby protect any object beingbuffed from being directly engaged by the circumferential edges of saidcanvas backings; a resilient circular backup plate having a radius equalto the inner radius of the outer annular area of the rear surface ofsaid edge guard pad, said backup plate being in engagement with saidrear surface; and fastening means coupling the centers of said buffeRpad, said edge guard pad, and said backup plate to each other, andadapted for attachment to the end of a rotatable drive shaft.
 2. Abuffing machine of the type used in the automotive service field and forother purposes including: a buffer pad comprising a circular canvasbacking provided with a nap of wool on the front surface thereof, anedge guard pad comprising a circular canvas backing provided with a napof wool on the outer annular area of the rear surface thereof, said padsbeing assembled with the rear surface of the canvas backing for thebuffer pad held adjacent the front surface of the canvas backing for theedge guard pad, the nap on the outer circumferential edge of the frontsurface of the buffer pad and the nap on the outer circumferential edgeof the rear surface of the edge guard pad tending to lean radiallyoutwardly such that they meet in the common plane of the canvas backingsfor the pads and thereby provide for covering the circumferential edgeof said buffer pad, a circular backup plate for said buffer pad, andsaid circular backup plate having a radius equal to the inner radius ofthe outer annular area on the rear surface of the canvas backing of theedge guard pad that is provided with a nap of wool.
 3. The invention inaccordance with claim 2 wherein said circular back-up plate is formed ofrubber.
 4. The invention in accordance with claim 3 wherein said bufferand edge guard pad assembly is provided with a central opening, whereinsaid back-up plate is provided with a central opening in line with thecentral opening of said pad assembly, and wherein said buffing machineincludes a driving spindle having a threaded projected end that extendsfrom the rear of said back-up plate through the central opening of saidback-up plate and said pad assembly, and a clamping nut provided with acap, said nut being inserted from the front of said pad assembly intothe central opening thereof such as to engage the threaded projected endof said spindle to enable the cap thereon to clamp the inner edge of thecentral opening of said pad assembly against said back-up plate.